Geoege l



(No Model.)

G. L. REBCB.

SCREW PLATE.

No. 320,693. Patented June Z3, 1885.

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www I Mmw UNITED STATES PATENT OFFICE.

GEORGE L. REECE, OF DERBY LINE, VERMONT, ASSIGNOR TO FRED D. BUTTERFIELD AND H. STEVART HASKELL, OF SAME PLACE.'

SCREW-PLATE.

SPECIFICATION forming part of Letters Patent No. 320,693, dated June 23,1885.

Application filed December 31, 1884. (No model.)

To @ZZ whom, it may concern:

Beit known that I, GEORGE L. REECE, a citizen of the Dominion of Canada, residing at Derby Line, in the county of Orleans and State of Vermont, have invented certain new and useful Improvements in Screw-Plates, of which the following is a specication, reference being had therein to the accompanying drawings.

My invention relates to that class of screwplates in which a hub or collet for holding the divided die is interposed between the die and the stock.

The object of my invention is to provide a screw-plate in which the divided die shall be held in position in such a manner as to prevent any motion of the same in relation to the collet when in operation, and also to prevent any lnotion of one part of the die in relation to the other, thereby preventing cooking77 or tilting of the die and the product-ion of an imperfect screw thread-in short, to make of an adjustable die a solid die for the time being.

In the accompanying drawings, in the various gures of which the same letters designate like parts, Figure l is a side elevation of the complete collet, consisting of the body a and the cap b. Both are threaded and screwed together. Fig. 2 is a vertical section of the collet with the die in place, and showing in detail the construction of the several parts. Fig. 3 shows the guide side of the collet with the guide-jaws d d d d and the chipways e e e c. Fig. 4 is a top plan view of the collet with the cap bin place, and shows through the opening in the cap the cutting-jaws ,of the die c c. Fig. 5 is a top plan view of the body of the collet with the cap removed, and showing the divided die c c in position.

The screws ff (shown in Figs, l, 2, and 5,) serve the purpose of adjusting the parts of the die relative to each other and to the guide jaws dddd. Adjustment is ordinarily :required only to compensate for wear of the die and corresponding tap. The heads of the screws, when the die is adjusted, do not project from the collet, which is designed to enter a circular opening in the stock,where it is held by a pointed set-screw entering the conical depression h in the body of the collet. Another conical depression is made in cap at z', whereby an easy and expeditious method of attaching t-o and separating the cap from the body is obtained in the manner following: The pointed set-screw, heretofore mentioned, is made to engage with the cap instead of the body, and the insertion ofa piece of iron of oblong section (held in a vise) into the space e, Fig. 3, gives resistance to the revolution of the body, when by a rotary movement of the stock the cap is unserewed or screwed on. The cap b, when in position, is screwed down upon the die, covering nearly its entire surface, and holds it solidly within the chambered collet, the die resting upon the bottom or floor of the chamber. It will be understood that the oflice of the cap is to prevent the tilting of one or both part-s of the die, in addition to its apparent function of preventing the die from falling out or moving in a line with the axis of the collet.

I am aware that solid dies are commonly held in position by a cover variously attached to the stock, and I do not claim the cap for this purpose; but its otlice, as indicated, is to keep each part of the divided die in exactly the same plane with the other part. An advantage over some screw-plates now in use is that as the die is set in the body of the collet, instead of in the cap, the chipways in the die and collet always coincide, forming clear passages in a straight line.

It will be observed that the die used is rectangular in outward form and lit-s closely a rectangular chamber in the collet, whereby the die is held more iirmly and solidly than is possible with a circular die in a circular chamber.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent- The combination, with the circular collet having the guidingjaws d d and the rectangular recess for containing the die, of the cap or cover b, screwed upon the collet andv retaining the die within the recess, substan tially as described.

In testimony whereof I affix my signature in presence of two witnesses.

GEO. L. REEGE. Vitnesses:

WM. J. FosrEn, A. K. DARLING. 

